The number of minutes Pam talked on the phone was 35, 40, 12, 16, What was the average time Pam was on the phone

Which equation and solution can be used to solve this problem? thirteen less than a number is sixteen. 13-n=16: add 13 to both sides. the answer is 29. n+13=16: subtract 13 from both sides. the answer is 3. n+16=13 subtract 13 from both sides. the answer is 3. n-13=16: add 13 to both sides. the answer is 29.

Lisa has three classes that each last 50 minutes. what is the total number of minutes of the three classes

Need solving this second acceleration problem.